Analysis of Hydrogenation Properties of Nuclear Fuel Zirconium Alloy Cladding

Abstract During the service of the reactor, the zirconium alloy will inevitably interact with hydrogen to form zirconium hydride, which will adversely affect its mechanical properties. In this paper, the first-principles software VASP is used to analyze the phase transition of zirconium hydride, and based on the results, the subprogram of MAAP4 integrated analysis for severe accidents is optimized to further analyze the interaction between zirconium alloy cladding and hydrogen. Verification. The results show that the diffusion equation has large calculation potential and high calculation accuracy for the effect of zirconium hydride with obvious phase transition, and can realize the hydrogen performance analysis of the cladding material in the reactor. At the same time, VASP shows that δ – ZrH1.5 is the main component of cladding material hydrogenation It is also the main reason for brittle transition.